What Is Hay Fever? What Is Allergic Rhinitis? What Causes Hay Fever?

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Main Category: Allergy
Also Included In: Ear, Nose and Throat;  Immune System / Vaccines
Article Date: 14 Aug 2009 - 0:00 PDT

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Hay fever (or hayfever) also known as allergic rhinitis, is a common condition that shows signs and symptoms similar to a cold with sneezing, congestion, runny nose and sinus pressures.

It is caused by an allergic response to airborne substances, such as pollen - unlike a cold which is caused by a virus. The time of year you get hay fever depends on what airborne substance you are allergic to.

Hay fever does not mean that the person is allergic to hay and has a fever. Hay is hardly ever an allergen, and hay fever does not cause fever.

Although hay fever and allergic rhinitis have the same meaning, most lay people refer to hay fever only when talking about an allergic reaction to pollen or airborne allergens from plants or fungi, and understand allergic rhinitis as an allergy to airborne particles, such as pollen, dust mites or pet dander which affect the nose, and maybe the eyes and sinuses as well.

The rest of this article focuses on hay fever caused by pollen and other airborne allergens that come from plants or fungi. Hay fever caused by pollen is also known as pollinosis.

Some people are only mildly affected by hay fever and rarely reach a point where they decide to seek medical advice. However, for many, symptoms may be so severe and persistent that they are unable to carry out their daily tasks at home, work or at school properly - these people will require treatment. Treatments may not get rid of the symptoms altogether, but they usually lessen them and make it easier to cope.

As with other allergies, the symptoms are a result of your immune system mistaking a harmless substance as a harmful one, and releasing chemicals that cause the symptoms.

It is estimated that about 20% of people in Western Europe and North America suffer from some degree of hay fever. Although hay fever can start affecting people at any age, it generally develops during childhood or perhaps early adulthood. The majority of hay fever sufferers find their symptoms become less severe as they get older.

What are the symptoms of hay fever?

Symptoms of hay fever may start at different times of year, it depends on what substance the patient is allergic to. If a person is allergic to a common pollen, then when the pollen count is higher his symptoms will be more severe.

Common symptoms include:

• Sneezing
• Watery eyes
• Itchy throat
• Itchy nose
• Blocked/runny nose

Severe symptoms may include:

• Sweats
• Headaches
• Loss of smell and taste
• Facial pain caused by blocked sinuses
• Itchiness spreads from the throat, to the nose and ears

Sometimes hay fever symptoms can lead to:

• Tiredness (fatigue)
• Irritability
• Insomnia

People with asthma may find that when hay fever symptoms emerge their wheezing and episodes of breathlessness become more severe. A significant number of people only have asthma symptoms when they have hay fever.

What are the causes of hay fever?

Hay fever occurs when the immune system mistakes a harmless airborne substance as a threat. As your body thinks the substance is harmful it produces an antibody called immunoglobulin E to attack it. It then releases the chemical histamine which causes the symptoms.

There are seasonal hay fever triggers which include pollen and spores that will only cause symptoms during certain months of the year.

The following are some examples of hay fever triggers:

• Tree pollen - these tend to affect people in the spring.
• Grass pollen - these tend to affect people later on in the spring and also in the summer.
• Weed pollen - these are more common during autumn (fall).
• Fungi and mold spores - these are more common when the weather is warm.

What are the risk factors for hay fever?

A risk factor is something that increases a person's chances of developing a disease or condition. Below are some risk factors for hay fever:

• Family history (inheritance, genetics) - if you have a close family member who has/had hay fever, your risk of developing it yourself is higher. There is also a slightly higher risk if a close family member has any type of allergy.


• Other allergies - people with other allergies are more likely to suffer from hay fever as well.


• Asthma - a significant number of people with asthma also have hay fever.


• Gender and age - hay fever affects more young males than young females. Before adolescence, twice as many boys as girls have hay fever. However, after adolescence many boys outgrow it and slightly more girls than boys are affected.


• Birth date - people born during the high pollen season have a slightly higher risk of developing hay fever than other people.


• Second-hand smoke - infants and babies who are regularly exposed to cigarette smoke during their first years of life are more likely to develop hay fever than babies who aren't.


• Being the first child - a higher percentage of firstborn children eventually develop hay fever, compared to other people.


• Babies from smaller families - a higher proportion of babies with no siblings, or just one sibling develop hay fever later on compared to babies born to larger families.


• Babies born to high income families - babies born to families with a high standard of living have a higher risk of developing hay fever later on, compared to other babies.

Experts believe that the last three risk factors are linked to childhood infections. If a baby and/or small child has had fewer infections, there is a greater risk of autoimmune problems.

How is hay fever diagnosed?

Generally, doctors can make a diagnosis based on the symptoms, which are usually fairly obvious. The doctor will also ask questions about the patient's personal and family medical history, and how signs and symptoms have been dealt with so far.

A blood or skin test can be followed up to identify which substance(s) the patient is allergic to.

• Skin test - the skin is pricked with a minute amount of a known allergen (substance that some people are allergic to). The amount of IgE antibodies (immunoglobulin E) is measured. IgE antibodies are produced in high amounts if a person has an allergy to something.


• Blood test - the test simply measures the level of IgE antibody in the blood. If it is zero there is no sensitivity, whereas 6 indicates very high sensitivity.

What are the treatment options for hay fever

There is a vast array of OTC (over-the-counter) and prescription medications for treating hay fever symptoms. Some patients may find that a combination of two or three medications works much better than just one.

It is important for parents to remember that some hay fever medications are just for adults. If you are not sure, talk to a qualified pharmacist, or ask your doctor.

Medications include:

• Antihistamine sprays or tablets - these are commonly available over the counter. The medication stops the release of the chemical histamine. They usually effectively relieve symptoms of runny nose, itching and sneezing. However, if your nose is blocked they don't work.
  
  Newer antihistamines are less likely to cause drowsiness than older ones - but older ones are just as effective. Examples of OTC antihistamines include loratadine (Claritin, Alavert) and cetirizine (Zyrtec). Examples of prescription antihistamines include Fexofenadine (Allegra) and the nasal spray azelastine (Astelin). Azelastine starts working very rapidly and can be used up to 8 times a day - however, it can cause drowsiness and leave a bad taste in the mouth after use.


• Eye Drops - these reduce itching and swelling in the eyes and are usually used alongside other medications. Eye drops containing cromoglycate are commonly used.


• Nasal Corticosteroids - These sprays treat the inflammation caused by hay fever, and are a safe and very effective long-term treatment. Examples include fluticasone (Flonase), fluticasone (Veramyst), mometasone (Nasonex) and beclomethasone (Beconase). Most patients may have to wait about a week before experiencing any significant benefits. Some patients may notice an unpleasant smell or taste, and have nose irritation.


• Oral corticosteroids - for very severe hay fever symptoms the doctor may prescribe prednisone in pill form. They should be prescribed only for short-term use, because of their long-term link to cataracts, muscle weakness and osteoporosis.

Desensitization treatment (immunotherapy) - this treatment used to be more common in the UK, but is now very rarely used and is not used at all in the USA, because it can cause some very strong reactions. Increasing amounts of the allergen are introduced into the patient. This treatment is only done in very specialized centers for patients with severe symptoms.

Alternative therapies - some alternative therapies claim to treat hay fever effectively.

A study published in The Medical Journal of Australia carried out by researchers at the University of Melbourne, suggested that acupuncture is effective in the symptomatic treatment of persistent allergic rhinitis. (MJA 2007; 187 (6): 337-341).

It is important to remember that although some patients do report benefits from alternative therapies, a lot of information one reads in books and on the internet is anecdotal. For therapy to be convincing, it should undergo proper clinical tests which are either compared to a placebo (dummy treatment) or some treatment known to be effective. Before undergoing any complementary/alternative therapy, check it out carefully.

How to prevent hay fever

There is not much you can do to prevent yourself from becoming allergic to pollen or allergens from plants or fungi. However, avoiding situations where your exposure might be high will help reduce the likelihood of an allergic reaction, or perhaps its severity. The following measures may be helpful:

• Be aware of the pollen count during your susceptible months. You can get information from the TV, radio, internet or daily newspapers. On humid and windy non-rainy days pollen counts tend to be higher. Pollen counts tend to be higher during the early evening.


• Keep windows and doors shut when pollen is high.


• Avoid mowing the lawn altogether during your susceptible months.


• Choose low pollen days for gardening.


• Keep away from grassy areas when pollen counts are high.


• Regularly splash your eyes with cool water. It will sooth them and clear them of pollen.


• If pollen counts are high and you come indoors, have a shower and change your clothes.


• Remember that wrap-around glasses protect your eyes from pollen getting through.


• A hat helps prevent pollen from collecting in your hair and then sprinkling down onto your eyes and face.


• When driving on a high count day or time of day keep windows closed. There are pollen filters for cars.


• Do not have flowers inside your home.


• Keep your surfaces, floors, carpets as dust free as possible.


• If you use a vacuum cleaner make sure it has a good filter.


• Ask smokers not to let their smoke get near you.


• If you are a smoker, giving up will help reduce your symptoms.


• Pets can bring in pollen from outside. Whenever a pet comes indoors on a high pollen count day, either wash it or smooth its fur down with a damp cloth. Sometimes pets can be a source of allergic rhinitis which makes your pollen allergy worse.


• Smear Vaseline around the inside edges of your nostrils - it helps stop pollen from getting through.


• If you know when your hay fever season starts, prepare yourself in advance. See your GP and ask him/her to develop a plan for you.

Written by Joseph Nordqvist
Edited by Christian Nordqvist


Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today